With opinion polls projecting a historically close result on Tuesday, Trump and Harris stuck to familiar themes during campaign stops on Saturday.
At a rally in Gastonia, North Carolina, Trump said he would deport millions of immigrants if elected and warned that if Harris were to win, "every town in America would be turned into a squalid, dangerous refugee camp".
Harris said the former Republican president would abuse his power if he returns to the White House.
"This is someone who is increasingly unstable, obsessed with revenge, consumed with grievance, and the man is out for unchecked power," she said.
More than 72 million Americans have already cast ballots, according to the Election Lab at the University of Florida, below the record early-voting pace in 2020 during COVID-19, but still indicating a high level of voter enthusiasm.
Harris plans appearances with rock star Jon Bon Jovi in Charlotte, the biggest city in North Carolina, which is tied with Georgia for the second-biggest prize of the swing states.
Each has 16 votes in the Electoral College, where 270 are needed to secure the presidency.
More than 72 million Americans have already cast ballots ahead of Tuesday's election, experts say. (AP PHOTO)
North Carolina backed Trump in 2020 but elected a Democratic governor on the same day, giving hope to both parties.
Some four million votes have already been cast in North Carolina, and the western counties that have been devastated by Hurricane Helene appeared to be voting at roughly the same rate as the rest of the state, according to Catawba College political science professor Michael Bitzer.
Trump criticised the federal government's response to the disaster and repeated his false claim that aid had been diverted from the state to help immigrants entering the country.
He also said that residents of US suburbs, traditionally seen as a refuge from crime and other dangers, are under threat.
"The suburbs are under attack right now. When you're home in your house alone, and you've got this monster that got out of prison, you know, six charges of murdering six different people," he said.
Violent crimes dropped in the US last year. However, Trump and his allies have emphasised crime on the campaign trail and falsely suggested immigrants are responsible.
Harris and Trump have very different policies on major issues including support for Ukraine and NATO, abortion rights, immigration, taxes, democratic principles and tariffs.
Harris and Trump were both in North Carolina on Wednesday, Nevada on Thursday and Wisconsin on Friday - all battleground states - at one point holding events around 11km from each other.
It indicates the enormous effort put on persuading a relatively small number of voters in a few states, because the other states are seen as safely Democratic or Republican.
But Trump will also visit Salem, Virginia, on Saturday despite polls showing a clear lead there for Harris.
Heading into the final stretch, on Monday the Harris campaign plans to hold simultaneous interconnected organising events across all seven battleground states to mobilise voters, according to a senior campaign official.
